With Steam having a gaming audience I’d argue that this has at least a slight bias towards Arch, as the latest kernel versions and other software are often advantageous for gaming in particular.
But even with the Steam numbers note that Arch is just listed as one single variant, while Ubuntu has separate entries for different versions. Ubuntu LTS 22.04 alone is so close to Arch that it’s probably ahead once you include all versions.
If we are talking about desktop PCs, maybe Ubuntu, but based these reports it’s Arch.
https://store.steampowered.com/hwsurvey/Steam-Hardware-Software-Survey-Welcome-to-Steam%3Fplatform%3Dlinux&ved=2ahUKEwjdg9iH-d2FAxXjppUCHVjoCJUQjjh6BAgbEAE&usg=AOvVaw208M9_ZU0zQ2BXwz8ei5Oa
https://youtu.be/8V8uQbIFlh0?si=Zc-AG7Ojf1V0y8sT
Worth keeping in mind that the steam deck uses a distro based on arch, so it might be inflating the arch numbers in that steam survey.
With Steam having a gaming audience I’d argue that this has at least a slight bias towards Arch, as the latest kernel versions and other software are often advantageous for gaming in particular.
But even with the Steam numbers note that Arch is just listed as one single variant, while Ubuntu has separate entries for different versions. Ubuntu LTS 22.04 alone is so close to Arch that it’s probably ahead once you include all versions.